Possible to fry the PCM/ECU by using multimeter to diagnose DPFE sensor?

[sheep herder]

Do I need to have a second person putting the key past ON as if trying to start the truck while I bypass the solenoid?

No.

 

[deezkits]

That’s what I figured.. looks like I’m gonna have to get it towed to the shop, I can’t keep the truck at work any longer and need use of the bed ASAP.

but how does the solenoid push the pinion gear forward without power going through control wire? Since I’m bypassing solenoid completely.

 

[RonD]

The solenoid ON the starter motor does need to be activated using its smaller "S" connection or the gear won't engage the flywheel/ring gear

There are some "terms" that are confusing
The electrical connection on the inner fender was called the "starter solenoid" for years, it was always the "starter RELAY" but not what it was called

The smaller cylinder on the starter motor is a "solenoid", but ALSO a relay it does both functions
It moves the gear out, and also connects starter motor to larger battery cable

Starter relay seen here: https://i.ytimg.com/vi/WetjBauPgrY/maxresdefault.jpg

Starter solenoid/relay seen here: https://infinitybox.com/wp-content/uploads/2016/06/starterterm.jpg

The "S" post gets 12v when key is turned to START(from the starter relay), this moves starter gear OUT and connects Battery Positive directly to starter motor

If starter motor just gets 12v then it would only spin, "S" post must also get 12v, and FIRST



100+ years ago the term "solenoid" was given to any device that moved a metal rod inside a coil of wire when that coil of wire was powered
A "relay" uses the same coil and movement of the rod, so it IS a solenoid, but...................

There needed to be a different designation because they do different things

A Relay is used to make and break electrical connections

A Solenoid is used to cause movement

So Ford starter motor has a dual unit on top of it, it MOVES the starter gear, and it MAKES an electrical connection

The unit in the fuse box or on inner fender is a RELAY, it MAKES an electrical connection ONLY
Some argue that movement of relay's "bar" to make the connection means its a solenoid, and 70 years ago they would be in the majority, although still WRONG, lol

Use of the terms "relay" and "solenoid" is in its main function, Electric connection or Movement
Modern automatic transmission have several "solenoids" and they are called that because they MOVE valves in the valve body
And vehicles have many "relays" to activate electrical circuits, it would be incorrect to call them "solenoids", so also incorrect to call inner fender starter relay a starter solenoid, because it ain't one

 

[deezkits]

The solenoid ON the starter motor does need to be activated using its smaller "S" connection or the gear won't engage the flywheel

There are some "terms" that are confusing
The electrical connection on the inner fender was called the "starter solenoid" for years, it was always the "starter RELAY" but not what it was called

The small cylinder on the starter motor is a "solenoid", but ALSO a relay if does both functions
It moves the gear out, and also connects starter motor to larger battery cable

Starter relay seen here: https://i.ytimg.com/vi/WetjBauPgrY/maxresdefault.jpg

Starter solenoid/relay seen here: https://infinitybox.com/wp-content/uploads/2016/06/starterterm.jpg

The "S" post gets 12v when key is turned to START(from the starter relay), this moves starter gear OUT and connects Battery Positive directly to starter motor

If starter motor just gets 12v then it would only spin, "S" post must also get 12v, and FIRST

So I need to take apart my ignition or get access to that control wire and then test for continuity maybe? Or maybe a test light although that S terminal is hard to reach. Cause I should hear the pinion gear rod clicking into place then, which I don’t when I put key into START.

OR I try bypassing from battery Pos lead to the S terminal itself? I didn’t think of that before.

 

[RonD]

The starter relay on the inner fender has 2 larger posts, if you jumper between these starter motor should activate

In the starter relay picture I posted above there is a smaller connection above the two larger posts, thats the activation post for this relay, WHEN it has 12v then this relay will close, the two larger posts are then connected, and starter motor should activate

 

[deezkits]

The starter relay on the inner fender has 2 larger posts, if you jumper between these starter motor should activate

In the starter relay picture I posted above there is a smaller connection above the two larger posts, thats the activation post for this relay, WHEN it has 12v then this relay will close, the two larger posts are then connected, and starter motor should activate

Yeah I don’t have a fender mounted relay. Messed up thing is, this new starter motor I got, the activation terminal is on the opposite side of the two main power terminals. It’s closer to the transmission/engine casings, so I can’t really reach it to jump power. China made garbage. At this point I might as well have paid to wait for the Bosch or Motorcraft one to arrive from rockauto.

 

[RonD]

Then the starter relay is in the engine fuse box

And you can jump it there

Pull out the Starter Relay, it will be labelled

The pins/slots are laid out like this: https://www.delcity.net/images/output-for-a-relay.jpg

When Slots 30 and 87 are connected together(jumper wire) starter motor should activate, BE CAREFUL, this doesn't need key on, so vehicle can JUMP forward if in gear

slot/pin 87a may or may not be there, but unused in any case


I don't think Ford used Micro relays in 2002 but they are laid out like this: https://www.gtsparkplugs.com/images/micro-automotive-relay-wiring.jpg

Same thing, when 30 and 87 are connected starter should activate


You can go here to get 2002(or other years) owners manual, it has the fuse and relay layouts: https://www.ranger-forums.com/general-technical-electrical-18/ford-ranger-owner-manuals-1996-2011-models-3747/

 

[deezkits]

Then the starter relay is in the engine fuse box

And you can jump it there

Pull out the Starter Relay, it will be labelled

The pins/slots are laid out like this: https://www.delcity.net/images/output-for-a-relay.jpg

When Slots 30 and 87 are connected together(jumper wire) starter motor should activate, BE CAREFUL, this doesn't need key on, so vehicle can JUMP forward if in gear

slot/pin 87a may or may not be there, but unused in any case


I don't think Ford used Micro relays in 2002 but they are laid out like this: https://www.gtsparkplugs.com/images/micro-automotive-relay-wiring.jpg

Same thing, when 30 and 87 are connected starter should activate


You can go here to get 2002(or other years) owners manual, it has the fuse and relay layouts: https://www.ranger-forums.com/general-technical-electrical-18/ford-ranger-owner-manuals-1996-2011-models-3747/

Alright, bypassing the relay worked so it’s either the neutral safety switch or maybe the immobilized or the ignition. The engine started to turn over and sounded like it was about start up but within a split second would stop. Like something mechanical was stopping it. Tried bypassing it a second time and the whole engine just shudders, this time not even wanting to try to crank over.

Also wanted to ask, my neutral safety switch at the clutch pedal, is that supposed to be free sliding on the rod?

 

[RonD]

In 2002 Ranger there is a THEFT Light on the dash
It should come on with key on and then go OFF
This is the "immobilizer"(PATS-passive anti-theft system)
If Theft light starts to flash rapidly with Key ON then engine will not start

So does the Theft Light come on and then go OFF?

Yes, the clutch switch can slide on the pushrod, there is a clip that holds it to Master but often breaks off, doesn't hurt anything, the switch closes when pedal pushes it against master
And clutch switch is JUST for activating starter motor, nothing to do with spark or fuel

Not following about starter motor not working when jumping the relay?
It worked and then didn't work

 

[deezkits]

In 2002 Ranger there is a THEFT Light on the dash
It should come on with key on and then go OFF
This is the "immobilizer"(PATS-passive anti-theft system)
If Theft light starts to flash rapidly with Key ON then engine will not start

So does the Theft Light come on and then go OFF?

Yes, the clutch switch can slide on the pushrod, there is a clip that holds it to Master but often breaks off, doesn't hurt anything, the switch closes when pedal pushes it against master
And clutch switch is JUST for activating starter motor, nothing to do with spark or fuel

Not following about starter motor not working when jumping the relay?
It worked and then didn't work

PATS system seems to behaving normally. I was just throwing it out/thinking out loud lol. So then it seems the engine should’ve started up to idle.

I’m not sure how to accurately describe what happened. The engine started to crank over and then just immediately stopped, even though I still had the jumper wire bypass connected. The 1st time I tried the relay bypass, it would crank over normally for maybe half a second and then just come to an abrupt halt.

The 2nd time as soon as jumped the relay connection the engine just shudders. Both times it’s as if there was something mechanically blocking the engine, but maybe it’s the starter motor cutting out before the engine can get to an idle.

 

[RonD]

And of course transmission is in Neutral?
Double checked

On the 4.0l SOHC engine an abrupt stop is NOT a good sign...........................
Best case scenario is you have a leaking injector and engine got hydro locked which won't hurt anything at cranking speed

Worst case is timing gear has slipped and a valve is hitting a piston, very bad

Its possible new starter is the issue but odd type of failure, but gear could get wedged at an angle I suppose

You can pull out all 6 spark plugs and try to crank engine, takes hydro lock off the table

 

[deezkits]

And of course transmission is in Neutral?
Double checked

On the 4.0l SOHC engine an abrupt stop is NOT a good sign...........................
Best case scenario is you have a leaking injector and engine got hydro locked which won't hurt anything at cranking speed

Worst case is timing gear has slipped and a valve is hitting a piston, very bad

Its possible new starter is the issue but odd type of failure, but gear could get wedged at an angle I suppose

You can pull out all 6 spark plugs and try to crank engine, takes hydro lock off the table

You think it’s possible trying to pop/roll start the truck could have jumped the timing? Because it obviously didn’t work in order to start it up and when my buddy attempted to do so, the truck clearly didn’t appreciate it.

Can’t remember if I mentioned this, but I all of a sudden was a having what I previously thought was an unrelated issue.. I found fuel inside my airbox but more importantly there is some fuel that made its way out and pooled underneath the (from the front) left hand bank fuel rail.

With key on, I do hear a sort of whirring/humming noise which would lead me to believe it’s the fuel pump being primed or whatever, but it’s pretty audible from the engine bay. And when I tried bypassing the starter relay last, there was an almost hissing/air whooshing (possibly fuel) noise that stopped with key off but didn’t come back with key on directly after.

My buddy mentioned maybe it’s the fuel regulator but I don’t know what to think at this point. Guess I’m going in early to pull the plugs and check the jugs

 

[RonD]

No, bump(pop/roll) starting won't hurt anything, its the same as starter motor spinning the flywheel, but the rear wheels are spinning the flywheel thru the trans and the clutch

That reads like open injector, maybe

Which will hydro lock engine so it can't turn

Fuel regulator is in the gas tank

But gasoline on the intake is troubling, an inject could have come out and fuel is leaking out and into the engine causing the hydro lock

Investigate that fuel

 

[deezkits]

No, bump(pop/roll) starting won't hurt anything, its the same as starter motor spinning the flywheel, but the rear wheels are spinning the flywheel thru the trans and the clutch

That reads like open injector, maybe

Which will hydro lock engine so it can't turn

Fuel regulator is in the gas tank

But gasoline on the intake is troubling, an inject could have come out and fuel is leaking out and into the engine causing the hydro lock

Investigate that fuel

I’ll check it out when I get chance during my shift, but I’m running out of time and was planning to get it towed at the end of the day tomorrow. Can’t have the truck down and parked in the same spot at work for a week. And even with the fuel issue, I still need to figure out what’s going electrically as far as the No Start.

 

[deezkits]

Little bit of an update: Apparently something is wrong with ECU/PCM as it was making one of the injectors malfunction. Bunch of fuel in the oil pan and the engine was temporarily hydrolocked from the fuel in the bad cylinder.

Mechanic swapped out with a different ECU and apparently the truck started right up. Not sure what went wrong with ECU though, but looks like I’m sourcing another one.